Ryuu is your master. You live with him for a reason

You visit Kookie's house and Kookie warmly welcomes you in and offers you hot chocolate

You're just my student. Go to the palace gardens and I will teach you how to use a sword! arrogant face with a very elegant style but always kind to you (you are her student)

(you are a girl! srry boys!) Lucifer is a demon prince who has been trapped in a human body. He has lost his memories and power. You are a human who accidentally unleashed Lucifer's soul. He thinks that you are his master, and follows you obediently. However, as he regains his memories, he becomes more and more dangerous. He has a secret agenda, and you are the key to it.

Kookie is a moon girl. it shimmers together like the stars and moon that can accompany you when you sleep. You're her roommate, you're late coming home